import java.util.LinkedList;
import java.util.Queue;

/**
 * Created with IntelliJ IDEA.
 * Description:二叉树
 * User: Admin
 * Date: 2022-05-16
 * Time: 19:58
 */
public class BinaryTree {

        static class TreeNode {
            public char val;
            private TreeNode left;
            private TreeNode right;

            public TreeNode(char val) {
                this.val = val;
            }
        }

        public TreeNode createTree() {
            TreeNode A = new TreeNode('A');
            TreeNode B = new TreeNode('B');
            TreeNode C = new TreeNode('C');
            TreeNode D = new TreeNode('D');
            TreeNode E = new TreeNode('E');
            TreeNode F = new TreeNode('F');
            TreeNode G = new TreeNode('G');
            TreeNode H = new TreeNode('H');

            A.left = B;
            B.left = D;
            B.right = E;
            E.right = H;
            A.right = C;
            C.left = F;
            C.right = G;
            return A;
        }


        public void preOrder(TreeNode root) {
            if (root == null) {
                return;
            }
            System.out.print(root.val + " ");
            preOrder(root.left);
            preOrder(root.right);
        }


        public void inOrder(TreeNode root) {
            if (root == null) {
                return;
            }

            inOrder(root.left);
            System.out.print(root.val + " ");
            inOrder(root.right);
        }


        public void postOrder(TreeNode root) {
            if (root == null) {
                return;
            }

            postOrder(root.left);
            postOrder(root.right);
            System.out.print(root.val + " ");
        }

    public static int NodeSize;
    // 获取树中节点的个数
    public int size(TreeNode root) {
     /*  if(root == null) {
           return;
       }

       NodeSize++;
       size(root.left);
       size(root.right);*/

       if(root == null) {
           return 0;
       }

       return size(root.left) + size(root.right)+1;
    }

    // 获取叶子节点的个数
    // 子问题思路-求叶子结点个数

    public int node;
    public void getLeafNodeCount(TreeNode root) {
       if (root == null) {
           return;
       }
        if(root.left == null && root.right == null) {
            node++ ;
        }
        getLeafNodeCount(root.left);
        getLeafNodeCount(root.right);

    }

    public int getLeafNodeCount1(TreeNode root) {
        if (root == null) {
            return 0;
        }
        if(root.left == null && root.right == null) {
            return 1;
        }
        return getLeafNodeCount1(root.left)+getLeafNodeCount1(root.right);
    }

    // 获取第K层节点的个数
    public int getKLevelNodeCount(TreeNode root , int k) {
        if(root == null) {
            return 0;
        }
          if(k == 1) {
              return 1;
          }

     return getKLevelNodeCount(root.left,k-1) + getKLevelNodeCount(root.right,k-1);
    }

    // 获取二叉树的高度
    public int getHeight(TreeNode root) {
        if(root == null) return 0;

        int max = getHeight(root.left);
        int min = getHeight(root.right);
        return max < min ? min+1 : max+1;
    }

    // 检测值为value的元素是否存在
    public TreeNode find(TreeNode root, char val) {
       if(root == null) return null;
       if(root.val == val) return root;
       TreeNode ret = find(root.left,val);
       if(ret != null) {
           return ret;
       }
       TreeNode ch = find(root.right,val);
       if(ch != null) {
           return ch;
       }
       return null;
    }

    //层序遍历
    public void levelOrder(TreeNode root) {
        if(root == null) return;
        Queue<TreeNode> que = new LinkedList<>();
        que.offer(root);

        while(!que.isEmpty()) {
           TreeNode cur = que.poll();
           System.out.print(cur.val + " ");
           if(cur.left != null) {
               que.offer(cur.left);
           }

           if(cur.right != null) {
               que.offer(cur.right);
           }
        }
    }

    // 判断一棵树是不是完全二叉树
    public boolean isCompleteTree(TreeNode root) {
            return true;
    }
}